The present invention is directed generally to cooling and drying fins for brake drums and flywheels and more particularly to such fins on the brake drums and flywheel of heavy duty trucks
Approximately eighty percent of the accidents involving the big 18-wheel tractor-trailer trucks are caused by wet brakes. To dry their brakes, truckers can power brake (drive with the left foot on the brake pedal) but this results in significant wear of the brake shoes and drums. Mechanical shields have been proposed to keep the brakes dry but these cut off air circulation and make the brakes and wheel bearings run much hotter. Custom brake drums have been proposed including means for directing air exteriorly into the space between the wheel and brake drum but these are positioned radially away from the braking surfaces and operate to attract moisture along with the air.
One solution proposed by this applicant and disclosed in copending patent application Ser. No. 710,227 filed Mar. 8, 1985, now U.S. Pat. No. 4,621,715, was to provide an elongated flexible strip adapted to wrapped around the peripheral wall of a brake drum adjacent the free interior edge thereof. A row of fins connected to the strip extended radially inwardly therefrom at a position adjacent to and interiorly of the interior edge of the brake drum to create a vacuum and effect a rush of air interiorly away from the brake drum both to dissipate moisture on the braking surfaces as well as prevent the entry of moisture from the ambient atmosphere. Whereas that invention has operated successfully, it has been found that other structure can accomplish substantially the same result by blowing air interiorly across the interior surface of a brake drum rather the sucking air thereacross.
Furthermore, it has been found that similar problems of heat and dust buildup are associated with the flywheel within the bell housing of the truck transmission. Dust and moisture tend to eat away at the flywheel and heat resulting from constant operation of the engine at approximately 2100-2300 RPM can produce stress cracks in the flywheel. Elevated operating temperatures furthermore reduce the life of the throw-out bearing and pilot bearing which therefore requires more frequent repairs and /or expensive overhauls.
A primary object of the invention therefore is to provide improved cooling and drying fins for brake drums and flywheels while in use on the road.
Another object is to provide such an apparatus for brake drums which is visually concealed and positioned so as not to interfere with inspection of or access to the brakes of a truck.
Another object is to provide such an apparatus readily suited for use with single or multiple axle vehicles and trailers.
Another object is to provide such an apparatus for the flywheel which will be operative to pull dust from the pressure plates and flywheel and create a cooling air flow for reducing the operating temperature of the flywheel and associated clutch structure.
Finally, an object is to provide the cooling and drying fins in structure which is economical to manufacture, easy to install and efficient in operation.